feat(tenancy): add resend invitation for pending team members

New resend_invitation() service method regenerates the token and
resends the invitation email for pending members.

Available on all frontends:
- Merchant: POST /merchants/account/team/stores/{sid}/members/{uid}/resend
- Store: POST /store/team/members/{uid}/resend

UI: paper-airplane icon appears on pending members in both merchant
and store team pages.

i18n: resend_invitation + invitation_resent keys in 4 locales.
Also translated previously untranslated invitation_sent_successfully
in fr/de/lb.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/modules/tenancy/services/store_team_service.py

@@ -907,6 +907,69 @@ class StoreTeamService:
         db.flush()
         return role
 
+    def resend_invitation(
+        self,
+        db: Session,
+        store: Store,
+        user_id: int,
+        inviter: User,
+    ) -> dict[str, Any]:
+        """
+        Resend invitation to a pending team member.
+
+        Generates a new token and resends the email.
+        Only works for pending invitations (not yet accepted).
+        """
+        store_user = (
+            db.query(StoreUser)
+            .filter(
+                StoreUser.store_id == store.id,
+                StoreUser.user_id == user_id,
+            )
+            .first()
+        )
+
+        if not store_user:
+            raise UserNotFoundException(str(user_id))
+
+        if store_user.invitation_accepted_at is not None:
+            raise InvalidInvitationTokenException("Invitation already accepted")
+
+        # Generate new token and update sent time
+        new_token = self._generate_invitation_token()
+        store_user.invitation_token = new_token
+        store_user.invitation_sent_at = datetime.utcnow()
+        db.flush()
+
+        # Get role name for email
+        role_name = store_user.role.name if store_user.role else "member"
+
+        # Send email
+        try:
+            self._send_invitation_email(
+                db=db,
+                email=store_user.user.email,
+                store=store,
+                token=new_token,
+                inviter=inviter,
+                role_name=role_name,
+            )
+        except Exception:  # noqa: EXC003
+            logger.exception(
+                f"Failed to resend invitation email to {store_user.user.email}"
+            )
+
+        logger.info(
+            f"Resent invitation to {store_user.user.email} for store "
+            f"{store.store_code} by {inviter.username}"
+        )
+
+        return {
+            "email": store_user.user.email,
+            "store_code": store.store_code,
+            "invitation_sent": True,
+        }
+
     def _send_invitation_email(
         self,
         db: Session,